From owner-freebsd-hackers@FreeBSD.ORG Mon Jul 4 07:25:41 2005 Return-Path: X-Original-To: hackers@freebsd.org Delivered-To: freebsd-hackers@FreeBSD.ORG Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 86ABE16A41C for ; Mon, 4 Jul 2005 07:25:41 +0000 (GMT) (envelope-from corecode@fs.ei.tum.de) Received: from stella.fs.ei.tum.de (stella.fs.ei.tum.de [129.187.54.7]) by mx1.FreeBSD.org (Postfix) with ESMTP id 0FE5043D49 for ; Mon, 4 Jul 2005 07:25:40 +0000 (GMT) (envelope-from corecode@fs.ei.tum.de) Received: from localhost (localhost [127.0.0.1]) by localhost.fs.ei.tum.de (Postfix) with ESMTP id 62A2F8DA9B; Mon, 4 Jul 2005 09:25:36 +0200 (CEST) Received: from stella.fs.ei.tum.de ([127.0.0.1]) by localhost (stella [127.0.0.1]) (amavisd-new, port 10024) with LMTP id 16314-05-3; Mon, 4 Jul 2005 09:25:32 +0200 (CEST) Received: from sweatshorts.fs.ei.tum.de (unknown [IPv6:2001:4ca0:0:fe00:0:5efe:a96:b4b4]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by stella.fs.ei.tum.de (Postfix) with ESMTP id C84D88D780; Mon, 4 Jul 2005 09:25:32 +0200 (CEST) Date: Mon, 4 Jul 2005 09:25:27 +0200 From: Simon 'corecode' Schubert To: Nikos Ntarmos Message-Id: <20050704092527.694c3057.corecode@fs.ei.tum.de> In-Reply-To: <20050704010908.GA17696@diogenis.ceid.upatras.gr> References: <000d01c57cf7$b9b6f9f0$29931bd9@ertpc> <20050630163126.GA7365@diogenis.ceid.upatras.gr> <001401c57ef0$dd489720$34bf5450@ertpc> <20050704010908.GA17696@diogenis.ceid.upatras.gr> X-Mailer: Sylpheed version 1.0.4 (GTK+ 1.2.10; i386-pc-dragonfly1) Mime-Version: 1.0 Content-Type: multipart/signed; protocol="application/pgp-signature"; micalg="PGP-SHA1"; boundary="Signature=_Mon__4_Jul_2005_09_25_27_+0200_9=zCeoo/_5gB51gV" X-Virus-Scanned: by amavisd-new at fs.ei.tum.de Cc: hackers@freebsd.org, andrit@ukr.net Subject: Re: hot path optimizations in uma_zalloc() & uma_zfree() X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 04 Jul 2005 07:25:41 -0000 --Signature=_Mon__4_Jul_2005_09_25_27_+0200_9=zCeoo/_5gB51gV Content-Type: text/plain; charset=US-ASCII Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Lately Nikos Ntarmos said: > Ummm... What compiler version are you use? The pointer variant produces > faster code for me on both NetBSD/alpha (gcc 3.3.3) and Linux/x86 (gcc > 3.3.5), using both -O0 and -O2 (other compiler flags also tested with > similar results). Perhaps something specific to FreeBSD then? I guess > I'll have to set up a FBSD box and have a look at it, when I catch up > with some of the other stuff in my todo list... This is micro-optimization at its best. I doubt it has any influence in real world scenarios. And if it does, something else is extremely broken. You don't want to takt the route and implement it in assembler? Besides, I guess it's totally CPU dependant, how stuff can be pipelined, all memory locations ought to be in the cache anyways. cheers simon --=20 Serve - BSD +++ RENT this banner advert +++ ASCII Ribbon /"\ Work - Mac +++ space for low $$$ NOW!1 +++ Campaign \ / Party Enjoy Relax | http://dragonflybsd.org Against HTML \ Dude 2c 2 the max ! http://golden-apple.biz Mail + News / \ --Signature=_Mon__4_Jul_2005_09_25_27_+0200_9=zCeoo/_5gB51gV Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.1 (DragonFly) iD8DBQFCyORsr5S+dk6z85oRAj0WAJ9AHFKz3lccxKIvZczxtCh3GMVIJwCg11iT WTkjSYfDvzorUtlYglOob7w= =3Vev -----END PGP SIGNATURE----- --Signature=_Mon__4_Jul_2005_09_25_27_+0200_9=zCeoo/_5gB51gV--